An expression vector encoding the fusion protein IL6 /IL2 has been constructed.After the flexible linker was synthesized and conjugated with IL2 gene fragment by PCRamplification, the IL6 gene fragment was unidirectionally inserted into the upstream tolinker-IL2 sequence. The molecule of IL6-linker-IL2 fusion gene named E.coli DH5 α/pfIL6/2 was cloned and identified by DNA sequencing. The expressed protein namedCH925 showed a strong band amounting to 32% of total cell protein on SDS-PAGE,with a molecular weight of 37.6kD. Its IL2 and IL6 specific activities assayed byCTLL-2 and 7TD1 cell lines were 2.1×10~6 and 2.3×10~8U/mg respectively following An expression vector encoding the fusion protein IL6 / IL2 has been constructed. After the flexible linker was synthesized and conjugated with the IL2 gene fragment by PCR amplification, the IL6 gene fragment was unidirectionally inserted into the upstream tolinker-IL2 sequence. The molecule of IL6-linker The expressed protein named CH925 showed a strong band amount to 32% of total cell protein on SDS-PAGE, with a molecular weight of 37.6 kD . Its IL2 and IL6 specific activities assayed by CTLL-2 and 7TD1 cell lines were 2.1 × 10 -6 and 2.3 × 10 -8 U / mg respectively